Fix http framework module that errors using SDK 2.1.801 (#15854)

- 2.1.801 seems to have a problem with:

```
						using (var uint8Buffer = Uint8Array.From(await request.Content.ReadAsByteArrayAsync ()))
```

sdks/wasm/framework/src/WebAssembly.Net.Http/WasmHttpMessageHandler.cs

@@ -93,7 +93,11 @@ private async Task doFetch (TaskCompletionSource<HttpResponseMessage> tcs, HttpR
 					if (request.Content is StringContent) {
 						requestObject.SetObjectProperty ("body", await request.Content.ReadAsStringAsync ());
 					} else {
-						using (var uint8Buffer = Uint8Array.From(await request.Content.ReadAsByteArrayAsync ()))
+						// 2.1.801 seems to have a problem with the line
+						// using (var uint8Buffer = Uint8Array.From(await request.Content.ReadAsByteArrayAsync ()))
+						// so we split it up into two lines.
+						var byteAsync = await request.Content.ReadAsByteArrayAsync ();
+						using (var uint8Buffer = Uint8Array.From(byteAsync))
 						{
 							requestObject.SetObjectProperty ("body", uint8Buffer);
 						}